The Reactivity of Pt n + Clusters With N 2 O Facilitated by Dual Lewis-Acid Sites.

The size dependence of metal cluster reactions frequently reveals valuable information on the mechanism of nanometal catalysis. Here, the reactivity of the Pt n + (n = 1-40) clusters with N 2 O is studied and a significant dependence on the size of these clusters is noticed. Interestingly, the small Pt n + clusters like Pt 3 + and Pt 4 + are inclined to form N 2 O complexes; some larger clusters, such as Pt 19 + , Pt 21 + , and Pt 23 + , appear to be unreactive; however, the others such as Pt 3 , 9,15 + and Pt 18 + are capable of decomposing N 2 O. While Pt 9 + rapidly reacts with N 2 O to form a stable quasitetrahedron Pt 9 O + product, Pt 18 + experiences a series of N 2 O decompositions to produce Pt 18 O 1-7 + . Utilizing high-precision theoretical calculations, it is shown how the atomic structures and active sites of Pt n + clusters play a vital role in determining their reactivity. Cooperative dual Lewis-acid sites (CDLAS) can be achieved on specific metal clusters like Pt 18 + , rendering accelerated N 2 O decomposition via both N- and O-bonding on the neighboring Pt atoms. The influence of CDLAS on the size-dependent reaction of Pt clusters with N 2 O is illustrated, offering insights into cluster catalysis in reactions that include the donation of electron pairs.